Monoazo dyestuffs



The present invention relates to new nionoaz o dyeistufis and to a process of making the same; m ore particularly it relates to mpnoazo dyestufis corresponding to the following general formula In this formula X stands for hydrogen or a simple sub-' stituent such as halogen or methyl, Y stands for hydrogen or cyclohexyl, and n stands for 1 or 2.

The new monoazo dyestufis are obtainable by coupling a diazotizedamine of the formula C I CH2 CHa-C wherein X and Y have the same meaning-as above, with l-amino-S-hydroxy-naphthalene monoor disulfonic acids substituted in theamino group by an acyl radical. V

The dia'zo-tized amines used in making the new monoazo dyestuifs can be obtained by fusing together o-nitrochlorobenzene .or its substitution products such as 2,41 dichloro-nitrobenzene, 2-nitro-3-chlorotoluene, 2,4-dichloror5-nitrotoluene, 4-chloro-3-nitrotoluene, 2-nitro-1,4-. dichlorobenzene, 3-nit'ro 1,2-dichl0robenzenewith" the alkali metal salts of 2-cyclohexylor 2,4-dicycloheXylphenols at elevated temperatures, e. g.- about 120- to 160 C.,f and subsequent reducing the nitro group inthe condensation product thus obtained. The cycloheXy1-Jphe'nols employed such asf' 2,-cyclohexylphenoland 2,4-dicyclo' hexylphenol or mixtures of thesame are easily accessible tentO "ice compounds which are obtained onatechnical 'scale by reacting phenol with chlorocyclohexane. Diazotization of the aminodiaryl ethers containing two cyclohexyl radicals is expediently carried out in solvents such as formic acid, formamide or alcohol."

Suitable coupling components of the above mentioned i d are e. cy de atives o .l-a i c-fiydm ynaphthalen 'mono; oi"- disulfonic 'aci'ds efgfof l-afiiin M u hydroxy-naphthalene-4-sulfonic acid, 1-amino-8-hydr6iry naphthalene-6-sulfonic-*acid, 1-amino=8-hydroxy-naphthalene-3,6-disulfoniciacid, 1-aniino 8-hydroxy-naphthalene- 4,6-disulfonic acid. As'N-acyl-sub'stitu'ents may be mentioned acyl radicals of the aromatic series such as the benzoyl radical, substituted benzoyl radicals, the benzene sulfoyl radical, substituted benzene sulfoyl radicals, further aliphatic acyl radicals such as th e acetyl radical, substituted acetyl radicals, higher fatty acid radicals or radicals as e. 'g.-'the trichloro acryloyl radical. 7

The new monoazo dyestuffs dye animal fibres and 'su'ch fibres asshow'a similar behavior in I dyeing, clear 'redto bluish-red shades 'of very good fastness to wet treatment i and goodgeneral fas't'ness properties; further they "partly" dy'eivefy w'ell froina neutral bath; In comparison 'with" the'known dyestuffs bearing a cyclohexyl radical'only inf p-pjosition' "to" the O-bri dge the new dyestuffs afe oistinguishediby a greater'clearnessof the shades. V

The following examples illustrate the invention without"? however, being'limited'thereto; the parts 'by'weight andi the parts by volume stand in the ratioof gramme to cubic centimetre. 7

Example] 7.8 parts by Weight of 2-amino-2' cyclolieiiyl-l,l-di phenyl ether are boiled with 7.0 parts by volume of 30% hydrochloric acid. and 25 part by volume of water-and the hydrochloride ofthis a-minodiphenyl ether is finely; distributed with good stirring. Ice is then added in quar tities so as to cause a temperature drop to 0 5 G and :1 20%, solution of 22 parts by weight of 'sodium nitrite is added in drops. After complete dissolution has been reached the solution is stirred for some time and the excess ofr'nitrous acid destroyed with amidosulfonicacid. The solution of the-diaz o compound is dropped into a solution" of 1 3.5 :parts, by weight of l-benzoylamino -8-hydroxy naphthalene-3,G-disulfonic acid in parts by volume of 15% sodium carbonate solution and 200 parts by volun eof ice Water, andthe mixture is stirred at roomteinperature for some hours. The coupling mixture isthen heatedto 7 0-80" ,C., the dyestufi precipitated by addition of sodium chloride, filtered and dried. A red powder is obtained which dissolves 'in" water with clear blue-red coloration and dyes wool clear 'bluish-red'shades of good fastness properties from aneut'ralbath or a bath con-" tainingfformic acid. When using as coupling components- 1- (2,5- di'chlorobenzoylamino)- S hydroxynaphthalenei 4,6-disulfonic acid, 1-(2Z4-dichlorobenzoylamino) 8- hydroxynaphthalene-4,6-disulfonio acid, l-benzoylamino- 8-hydroxynaphthalone-4,6:disulfonic acid, l-(diphenyl methane-a-carboylamino) 8 hydroxynaphthalene-3,6-di? sulfonic acid or 1-(2';4'-dichlorophenoxyacetylamino)-8-' hydroxynaphthalene-3,6-disulfonic acid ,dyestufis are :obtained, which dye Wool in clearless bluish-red shades of similar properties. When 1-benzoylamino-8-hydroxynaphthalenel-sulfonic acid is used as coupling compo? nent a dyestuff is obtained which dyes wool clear Bordeaux shades' from neutral bath;- A

Thus, the compound prepared using diazot'ized 2-ar'nino-" 2-cyclohexyl-l,l-diphenyl ether and l-(2',4-dichlor0- phenoxyacetylamino) 8 hydroxynaphthalene 3,6-disu1- fonic acid has the formula HO NH.CO.GHa.O-Cl

2-amino-2'-cyclohexyl-1,1'-diphenyl ether of the forniula which is employed as diazotizing component, can be obtained as follows:

200 grams of o-nitrochlorobenzene are introduced into a melt of 280 grams of o-cyclohexylphenol and a con? centrated aqueous solution of 90 grams of caustic alkali and stirred at 135-l40 C. for 8 hours. The melt is stirred with water and distilled in vacuo after decanting the water. B. P. 190-211 C. at 0.4 mm. pressure; yield: 80-85% of theory. The 2-nitro-2'-cyc1ohexyl-1,1'-diphenyl ether thus obtained is hydrogenated in alcoholic solution in the presence of Raney catalyst and the amine is distilled; B. P.l68-18 8 C. at 0.2 mm. pressure. The yield is almost quantitative. can be hydrogenated withfthe same result also without previous purification.

v Example 2 7.8 parts by weight of 2-amino-2-cyclohexyl-1,1-diphenyl ether are diazotized as described in Example 1 and the resultant diazo solution is dropped into a solution of 16.5 parts by weight of 1-(2',5'-dimethyl-4-'-ch1orob enzenesulfoylamino) 8 hydroxynaphthalene 3,6 disulfonic acid in 100 parts by volume of 15% sodium carbonate solution and 200 parts by volume of ice water. After stirring for some hours the solution is heated to 70-80 C., the dyestuff separated by addition of sodium chloride, filtered and dried. A red powder is obtained, which dyes wool clear bluish-red shades of good fastness properties from neutral or weakly acid bath. Dyestufis with similar properties are obtained when 1-(4'-methy1- benzene sulfoylamino) 8 hydroxynaphthalene 3,6- disulfonic acid is employed as coupling component.

Example 3 8.8 parts by Weight of 2-amino-5-chloro-2'-cyclohexyl- 1,1'-diphenyl ether are dissolved in 70 parts by volume of formamide and 10 parts by volume of 30% hydrochloric acid and a 20% aqueous solution of 2.2 parts by weight of sodium nitrite is added in drops at 0-5 C. After stirring for 30 minutes the excess nitrous acid is destroyed with amido'sulfonic acid and the solution of the diazo compound is dropped into a solution of 16.0 parts by weight of l- (2,5-dichlorobenzoylamino)-8- hydroxynaphthalene-4,6-disulfonic acid in 100 parts by volume of sodium carbonate solution and 300 parts by volume of ice water. After stirring for some hours the solution is heated to 70-80 C., the dyestutf precipitated by. addition of sodium chloride, filtered and dried. A red powder is obtained, which dyes wool clear The nitrodiphenyl ether;

red shades of good fastness properties from neutral or 2,785,168 a A r weakly acid 'bathl When 1-(2'-5-dimethyl-4'-ch1oro benzenesulfoylamino) 8 hydroxynaphthalene 3.6-, disulfonic acid is used as coupling component, a dyestufi is obtained which dyes wool clear bluish-red shades.

2-amino-5-chloro-2'-cyclohexyl-1,1'-diphenyl ether of the formula which is employed as diazo component, can be obtained by reacting 2,4-dichloronitrobenzene with a melt of'molar quantities of caustic alkali in o-cyclohexy1phenol at 120 C. and catalytically reducing the nitro group; B. P. 205-210 C. at 0. 6 mm. pressure.

Example 4 10.1 parts by weight of 2-amino-2',4'-dicyclohexyl- 1,1'-diphenyl ether are dissolved in 20 parts by weight of formic acid with heating; after cooling the solution to 0-5 C. 2.0 parts by weight of monohydrate and thereafter-a solution of 2.2 parts by weight of sodium nitrite in 4 parts by volume of Water are added in drops. After stirring for 30 minutes the excess nitrous acid is destroyed by introducing some solid amidosulfonic acid, the mixture is diluted with parts by volume of formamide and dropped into a solution of 13.5 parts by weight of l-benzoylamino 8 hydroxynaphthalene 3,6 disulfonic acid in 50 parts by volume of 25% ammonia solution, 200 parts by volume of ice water and 200 parts by volume of methanol. "After the coupling reaction is i complete the solution is heated to -70" C. and the dyestufi precipitated by addition of saturated sodium chloride solution, filtered and dried. powder which dyes wool from neutral or weakly acid bath clear bluish-red shades of very good fastness to wet treatment and good general fastness properties it has the formula i HOaS- OaH CHz-CH;

0% 011: CHz-CH:

benzoylamino 8 hydroxynaphthalene 4,6 disulfonicacid or 1 (4' methylbenzene sulfoylamino) 8- hydroxynaphthalene-3,6-disulfonic acid are used as coupling component or a mixture of 2-amino-2',4'-dicyclohexyl-1,1'-diphenyl ether and 2-amino-2'-cyclohexyl-1,1- diphenyl ether is employed as diazotizing component.

It is obtained as a red 2-amino-2',4'-dicyclohexyl-1,l' diphenyl ether of the which is employed as diazotizing component, can be obtained as follows: The technical distillation residues of monocyclohexylphenols yield in a quantity of about 30-40% by distillation a fraction of the B. P. l90200 C. at 0.2 mm. pressure as a viscous colorless oil, which is almost pure 2,4-dicyclohexylphenol. 150 grams of dicyclohexylphenol are homogeneously fused with 35 grams of caustic alkali, 105 grams of o-nitrochlorobenzene are introduced and the mixture is stirred at- 150-160 C. for 8 hours. The melt is stirred with water to remove the potassium chloride, separated from the aqueous phase and hydrogenated in the presence of Raney catalyst. By distillation a product of the B. P. 204-208 C. at 0.1 mm. pressure is obtained in a yield of 60-70% as a viscous oil of light yellowish color. It is also possible to employ a starting material of a wider boiling range and therefore of a higher proportion of monocyclohexylphenyl. In this manner a mixture of bases of a wider boiling range is obtained which, however, results in dyestufis of very similar properties.

We claim:

1. Monoazo dyestufis corresponding as free acids to the formula wherein X stands for a radical selected from the group consisting of hydrogen, chlorine and methyl, Y stands for a radical selected from the group consisting of hydrogen and cyclohexyl, n stands for one of the integers 1 and 2, and ac stands for an acyl radical.

2. The monoazo dyestufi corresponding as free acid to the formula HO NECO-G HOaS OIH 10 CHs-CH:

C \CH2 GHQ-C 5 3. The monoazo dyestufi corresponding as free acid to the formula H0 1;IH.oo.cH=.0-Oo1 N=N $1 v HO;S SOIH clan-0H,

4. The monoazo dyestutf corresponding as free acid -to the formula H0 NH.CO

HOaB 

1. MONOAZO DYESTUFFS CORRESPONDING AS FREE ACIDS TO THE FORMULA 